Table 9. Quality attributes of SaaS applications associated with customization.

Id	Quality attribute	Defination	References
QA 1	Multi-tenancy	SaaS services can support instances of simultaneous access by multiple users for multiple tenants.	Khanjani et al. (2014), La & Kim (2009)
QA 2	Scalability	SaaS providers can manage growth or decline in the level of services.	Khanjani et al. (2014), Lee et al. (2009), Nadanam & Rajmohan (2012), Zia & Khan (2012), Akojwar et al. (2012), CSMIC (2014)
QA 3	Availability	SaaS services can function within a specific time to satisfy users needs.	Khanjani et al. (2014), Lee et al. (2009), Nadanam & Rajmohan (2012), Akojwar et al. (2012), CSMIC (2014), Cancian et al. (2010), Alhamad, Dillon & Chang (2010)
QA 4	Reliability	SaaS application maintains operating and functioning under given conditions without failure within a given time period.	Khanjani et al. (2014), Lee et al. (2009), Nadanam & Rajmohan (2012), Akojwar et al. (2012), CSMIC (2014), Cancian et al. (2010), Alhamad, Dillon & Chang (2010)
QA 5	Maintainability	Modifications to the application are made by SaaS provider to retain it in the condition of good repair.	Khanjani et al. (2014), CSMIC (2014), Cancian et al. (2010)
QA 6	Security	The effectiveness of SaaS provider’s controls on service data, access to the services, and the physical facilities from which service are provided.	Khanjani et al. (2014), CSMIC (2014)
QA 7	Usability	The ease with which SaaS service can be used to achieve tenant-specific-goal.	Khanjani et al. (2014), Alhamad, Dillon & Chang (2010)
QA 8	Interoperability	SaaS service can easily interact with other services from the same SaaS provider or other providers.	Khanjani et al. (2014), CSMIC (2014), Cancian et al. (2010)
QA 9	Efficiency	SaaS services effectively utilize resources to perform their functions.	Khanjani et al. (2014), Lee et al. (2009), Nadanam & Rajmohan (2012), Akojwar et al. (2012)
QA 10	Functionality	SaaS application provides an extensive set of features.	Khanjani et al. (2014), CSMIC (2014)
QA 11	Accessibility	SaaS services are operable by users with different disabilities.	Khanjani et al. (2014), CSMIC (2014), Cancian et al. (2010)
QA 12	Commonality	SaaS services possess common features and are amenable to reuse by multiple users.	Khanjani et al. (2014), La & Kim (2009), Lee et al. (2009), Nadanam & Rajmohan (2012)
QA 13	Response time	SaaS application adheres to a defined time limit between service request and service response.	Khanjani et al. (2014), CSMIC (2014), Salama et al. (2012), Badidi (2013), Song et al. (2012), He et al. (2012), Wang et al. (2011)